A Few Relatively Simple "TENS" Circuits - CHEMELEC A Few Relatively Simple "TENS" Circuits. Origonally Created in 2002. Latest Revision: February 24, 2018 I initially designed these circuits for a friend who had muscle problems and while he says: "they did work well for him", I "DO NOT" RECOMMEND THE USE OF THESE DEVICES BY ANYONE FOR ANY REASONr use these Tens Devices Above the Neck. Transcutaneous Electrical Nerve Stimulator (TENS) Circuit A Transcutaneous Electrical Nerve Stimulation (TENS) device is, put bluntly, a machine for giving electric shocks. The author was prescribed such a device on loan by his orthopaedic specialist. The unit has a large number of programmes, of which he used only one. Circuit diagram: Transcutaneous Electrical Nerve Stimulator Circuit Diagram.